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macpokerstars

macrumors regular
Original poster
Sep 29, 2010
101
1
Hi,

Here are my SMART details for the Toshiba SSD I got with my mid-2010 Macbook Pro:

SSD wear level: 184%
Uptime: 18745 hours
Power cycle count: 7274

Are these very high?
What is a wear level of 100%? Does that mean I wrote an accumulate 128 GB of data to my disk?

Below is the detailed SMART report if it's relevant:




ID# ATTRIBUTE_NAME FLAG VALUE WORST THRESH TYPE UPDATED WHEN_FAILED RAW_VALUE

1 Raw_Read_Error_Rate 0x000a 100 100 000 Old_age Always - 0
2 Throughput_Performance 0x0005 100 100 050 Pre-fail Offline - 0
3 Spin_Up_Time 0x0007 100 100 050 Pre-fail Always - 0
5 Reallocated_Sector_Ct 0x0013 100 100 050 Pre-fail Always - 0
7 Unknown_SSD_Attribute 0x000b 100 100 050 Pre-fail Always - 0
8 Unknown_SSD_Attribute 0x0005 100 100 050 Pre-fail Offline - 0
9 Power_On_Hours 0x0012 100 100 000 Old_age Always - 18745
10 Unknown_SSD_Attribute 0x0013 100 100 050 Pre-fail Always - 0
12 Power_Cycle_Count 0x0012 100 100 000 Old_age Always - 7274
167 Unknown_Attribute 0x0022 100 100 000 Old_age Always - 0
168 Unknown_Attribute 0x0012 100 100 000 Old_age Always - 0
169 Unknown_Attribute 0x0013 100 100 010 Pre-fail Always - 678733152688
170 Unknown_Attribute 0x0013 100 100 010 Pre-fail Always - 64433684578
171 Unknown_Attribute 0x0000 100 100 000 Old_age Offline - 158
173 Unknown_Attribute 0x0013 184 184 100 Pre-fail Always - 141767278851
175 Program_Fail_Count_Chip 0x0013 100 100 010 Pre-fail Always - 0
192 Power-Off_Retract_Count 0x0012 100 100 000 Old_age Always - 93
 
Last edited:

scaredpoet

macrumors 604
Apr 6, 2007
6,628
360
I wouldn't worry TOO much about it, though you may want to consider saving up to get an OWC upgrade to replace your SSD.

The wear indicator is an estimation of what the manufacturer THINKS is the usable life of you SSD. Looks like quite a bit of writing happened, but as you can tell, a wear level of 100% or more doesn't mean the SSD just ups and dies immediately. In fact, there have been tests that she you can write hundreds of terabytes (and even petabytes) of data into an SSD before it starts failing.


You might want to look at getting an app like driveDX to get more detailed stats. The real indicator of imminent SSD failure is the reallocated sector count, and the used block reserve. As the former starts rising, the reliability of the drive suffers, and when you run out of reserve blocks, that's pretty much it for the drive.

In your case, it looks like there have been 0 reallocated sectors... which, I have to say, is pretty unusual for a nearly 5 year old drive that's been powered up as long as yours has. I'm wondering if the program you're using is giving you accurate info.
 

John6Plus

macrumors 6502
Sep 19, 2014
365
41
Holland, MI
I recently saw a study on SSD lifetimes which found the write cycles were underestimated by orders of magnitude. I wish I had the link handy.

Whether the same results would have been true 5 years ago I'm not sure, but I suspect it'd be pretty close. I've been using flash technology for years and have not had anything die due to suspected life cycles, including some old and heavily used USB drives.
 

Weaselboy

Moderator
Staff member
Jan 23, 2005
34,249
15,864
California
I recently saw a study on SSD lifetimes which found the write cycles were underestimated by orders of magnitude. I wish I had the link handy.

Probably this article?

OP> You are not getting reported errors, so I would just make sure you have good backups and keep on going. As others mentioned, these SSDs can often go far beyond what they are rated for.
 

yjchua95

macrumors 604
Apr 23, 2011
6,725
233
GVA, KUL, MEL (current), ZQN
I recently saw a study on SSD lifetimes which found the write cycles were underestimated by orders of magnitude. I wish I had the link handy.

Whether the same results would have been true 5 years ago I'm not sure, but I suspect it'd be pretty close. I've been using flash technology for years and have not had anything die due to suspected life cycles, including some old and heavily used USB drives.

You mean this?

http://techreport.com/review/27909/the-ssd-endurance-experiment-theyre-all-dead
 

John6Plus

macrumors 6502
Sep 19, 2014
365
41
Holland, MI
Neither one of those was the specific report I saw... but the conclusions are similar. The one I remember was dramatic, like I said, orders of magnitude - that may have been a specific brand.
 
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